diff options
| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2019-04-17 16:39:02 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-14 19:19:42 +0200 |
| commit | 025b9cf2a0fcaf8d971b8bea66f661cf3751c245 (patch) | |
| tree | f3669dba5f19c98016662bea725e0594d19f7bc8 | |
| parent | 1709284f082fbcb4a8e410242dcec3cc68389cda (diff) | |
x86/speculation/mds: Add 'mitigations=' support for MDS
commit 5c14068f87d04adc73ba3f41c2a303d3c3d1fa12 upstream.
Add MDS to the new 'mitigations=' cmdline option.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | Documentation/kernel-parameters.txt | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 5 |
2 files changed, 5 insertions, 2 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 5f81df18b2be..55a9bbbcf5e1 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2488,6 +2488,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. spectre_v2_user=off [X86] spec_store_bypass_disable=off [X86] l1tf=off [X86] + mds=off [X86] auto (default) Mitigate all CPU vulnerabilities, but leave SMT @@ -2502,6 +2503,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. if needed. This is for users who always want to be fully mitigated, even if it means losing SMT. Equivalent to: l1tf=flush,nosmt [X86] + mds=full,nosmt [X86] mminit_loglevel= [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index c2e07be3773c..6eef57e83af7 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -230,7 +230,7 @@ static const char * const mds_strings[] = { static void __init mds_select_mitigation(void) { - if (!boot_cpu_has_bug(X86_BUG_MDS)) { + if (!boot_cpu_has_bug(X86_BUG_MDS) || cpu_mitigations_off()) { mds_mitigation = MDS_MITIGATION_OFF; return; } @@ -241,7 +241,8 @@ static void __init mds_select_mitigation(void) static_branch_enable(&mds_user_clear); - if (mds_nosmt && !boot_cpu_has(X86_BUG_MSBDS_ONLY)) + if (!boot_cpu_has(X86_BUG_MSBDS_ONLY) && + (mds_nosmt || cpu_mitigations_auto_nosmt())) cpu_smt_disable(false); } |